In a large bowl, cream together butter and 1 1/2 cup sugar. Beat in eggs and vanilla. Combine flour, baking powder, baking soda and salt. Stir into the creamed mixture alternately with sour cream. Fold in apple pie filling and walnuts. Spoon batter into prepared muffin cups. Combine 1/4 cup sugar and cinnamon; sprinkle over the muffins.

Bake in preheated oven for 16 to 18 minutes, until a toothpick inserted into the center of a muffin comes out clean.